Reports on Industrial Group Meetings 2004

• Spring Meeting, Manchester 6^th to 8^th April 2004
  • Small Angle Scattering Sessions 6 ^th April 2004
  • Instrument Calibration Session 8 ^th April 2004
  • Catalysts in Industry 7 ^th April 2004
• Introduction To Powder Diffraction One Day Workshop 10^th June 2004
• Pharmaceutical SIG 5^th October 2004
• Autumn Meeting DIY Crystallography 4^th November 2004

BCA Spring Meeting

6-8^th April 2004, Manchester

A Report on The SAS Programme of the BCA Spring Meeting held at UMIST April 2004.

Photograph of speakers.

The SAS programme really started on Wednesday morning during the Instrument Calibration session with Dr.Manfred Kriechbaum from the Institute of Biophysics and X-Ray Structure Research, Austrian Academy of Sciences;

Practical Aspects of SAXS in Industrial Research:

In this talk the technical features, setup and application fields of a modern laboratory small-angle X-ray scattering camera in industrial research were presented. Emphasis was put on the nanostructural information content of SAXS in condensed heterophase (porous) systems, very common in industrial research and quality control, where SAXS can be an excellent complementary and even superior method (with respect to gas sorption methods) for the determination of inner surfaces and interfaces, as it 'sees' also enclosed pores and can be applied to wet samples. Industrial laboratories are also often faced with the task of high-throughput screening of multi-component formulations where the SAXS method can quickly yield nanostructural information when the SAXS camera is equipped with a flow-through sample cell attached to an autosampler. Furthermore, there is also the possibility to combine SAXS simultaneously with another thermal or spectroscopic method (E.g. simultaneous SAXS-DSC measurements).

To start the first parallel SAS session it was Vladimir Kogan of PANalytical with a presentation entitled Comparative SAXS Measurements Performed by Different Techniques

Nowadays modern laboratory x-ray diffractometers are being considered as possible platforms to perform SAXS experiments, challenging the performance of dedicated systems.

Vladimir presented the preliminary results of comparative SAXS measurements on polymers and bio-polymers, obtained using different experimental set-ups.

This was then followed by Manfred's second talk of the day;

Time-Resolved SAXS Measurements at Synchrotrons:

The high-flux and brilliance of X-rays from modern 3rd generation synchrotrons enable us to follow the nanostructural development, the supramolecular assembling or molecular mechanism of phase-transitions in situ and in real-time with a time-resolution in the millisecond time regime by small-angle X-ray scattering.

As examples, a variety of such time-resolved experiments, mostly on biological samples, performed at the SAXS beamline at ELETTRA, Trieste, Italy, were presented. Among them T-jump and p-jump relaxation studies on phospholipid phase-transitions followed by time-resolved SAXS as well as individual setups and current limitations were discussed.

This was followed by Mary Vickers with Solid Polymers to Particles in Solution which covered topics as diverse as;

Oriented lamellae in blown polyethylene film,
Lamellar repeat distances, tie molecules and mechanical properties,
Lyocell (Tencel) and voids,
Hair and breast cancer,
CaCO₃ in fuels & lubricants,
PbZrTiO₃ particles in suspension.

The final SAS session of the afternoon was from Andrew Harrison of Edinburgh University with "In-situ diffraction studies of microwave driven processes in materials chemistry and biology"

Andrew described how microwave heating is becoming increasingly important as a method of driving chemical synthesis and materials processes, both in solution, and in the solid state. He also highlighted the increasing concerns about the possible harmful effect that such radiation - as used in mobile 'phones - may have on biological tissue, over and above what might be expected from consideration of the likely heating effects at low exposure level. However, both aspects of this field are served by almost no direct experimental measurements of the nature of such effects.

The team at Edinburgh University have developed several different types of microwave reactor that enable them to perform X-ray or neutron scattering measurements on powders, single crystals, colloidal and liquid crystal systems during microwave irradiation, and to measure temperature accurately and precisely. He described the principles of designing and operating such equipment, and described some of their work on colloidal growth, and the potential to use such methods to probe the possible effect microwave radiation may have on the structure of proteins and biological membranes.

Thursday 8th April saw the Small Angle session kicking off with Dmitri Svergun of the European Molecular Biology laboratory - Hamburg Outstation With Small Angle Scattering Studies of Biological Macromolecules in solution.

Small-angle scattering of X-rays and neutrons (SAS) is a fundamental tool in the study of biological macromolecules. SAS allows one to study the structure of native particles in nearly physiological solutions and to analyse structural changes in response to variations in external conditions. The scattering data bears information about the overall shape and internal structure at a resolution of 1-2 nm. The method is applicable to a broad range of sizes, from individual macromolecules to multi-domain proteins and large macromolecular assemblies. Recent progress in instrumentation and data analysis significantly enhances resolution and reliability of structural models provided by the technique and makes SAS a useful complementary tool to high-resolution methods, in particular, in large-scale structural studies.

Advanced methods to analyse X-ray and neutron scattering data from solutions of biological macromolecules were presented including: ab initio low resolution shape determination; modelling of quaternary structure by rigid body refinement; ab initio analysis of medium-angle data to obtain domain structure from X-ray data; the use of specific deuteration combined with contrast variation in neutron scattering to construct detailed inhomogeneous structural models; addition of missing loops and domains to high resolution protein models; quantitative analysis of equilibrium mixtures of oligomeric proteins. Practical applications of the methods were illustrated by recent examples.

This was then followed by a chap called Richard Morris from Huntsman Surface Sciences, Oldbury with; "He Scrubs Up Well - Doesn't He?" or, New Aspects of Expanded Lamellar Surfactants - Aqueous, Sugar Based Exfoliates.

Currently there are two types of body scrub available; aqueous and non-aqueous.

Aqueous scrubs contain insoluble abrasives e.g. shells, seeds or pumice and are sold as pastes, gels or thickened emulsions.

Non-aqueous scrubs contain soluble abrasives i.e. sugar and salt. Oils, glycols and silicones are used in place of water.

The disadvantages of these products are that the aqueous scrubs are viscous, difficult to manufacture and the insoluble abrasives may lead to bacterial contamination. The non- aqueous scrubs are pastes, which have an oily or greasy feel, difficult to spread and are expensive.

However, it is now possible to produce water based sugar scrubs!

It has been discovered that surfactants can be made to form liquid crystals in saturated sugar solution.

We can see from the SAXS data that the inter-lamellar spacing is in the region of 500 A. These liquid crystals can support additional solid particles of sugar. The solid sugar crystals are suspended indefinitely and act as an exfoliate.

The presentation demonstrated the application of SAXS in the development of new surfactant technology and Richard also gave a brief demonstration of how to make you own sugar scrub from everyday chemicals found in the kitchen.

Markus Winter from Bruker then followed with SAXS from multi-functional XRD instruments; NanoSTAR - The Universe of Nanostructure Analysis that described the new Bruker XRD instrument.

Richard Heenan of ISIS at RAL delivered the final morning session;

SANS - Practicalities and prospects

Small angle neutron scattering, SANS, remains a powerful tool in many areas of science, despite many advances in X-ray instrumentation. Accelerator based, pulsed neutron sources, such as ISIS, are the way forward for the future of neutron scattering. Major new pulsed sources are under construction in the USA and Japan and a second target station, optimized for cold neutrons, is to be built at ISIS which will enable a new world class SANS facility within the UK.

The advantages of pulsed source SANS were outlined and examples given of SANS science from both LOQ at ISIS and the continuous source D22 instrument at the ILL reactor in Grenoble. SANS contrast variation, using deuterated components enables unique information to be obtained on increasingly complex systems. Complex sample environment such as pressure cells, flow and shear cells and stop-flow techniques are readily available to map system behaviour rather than simply measure single structures.

Thursday afternoon saw Pete Laity from Cambridge with Scattering from segmented Co-polymers - a reinterpretation of SAXS data;

Small-angle X-ray scattering (SAXS) has been widely used to study the microphase-separated morphology exhibited by polyurethanes, which arises through the immiscibility of 'hard' and 'soft' chain segments. The results are often analysed on the basis of a lamellar model, which appears to be justified on the basis of the expected volume fractions of 'hard' and 'soft' microdomains.

Peter's recent work has re-examined the SAXS data from a series of segmented co-poly (ether-urethane)s, using a number of alternative morphological hypotheses. The results suggest that a lamellar interpretation might not be the best model for polyurethane systems. On the contrary, the scattering data obtained from the co-poly(ether-urethane)s under various experimental conditions could be reproduced using 'globular' scattering models of the Zernike-Prins or Percus-Yevick types. This suggested relatively small volume fractions of hard segment microdomains and a significant persistence of segmental mixing. Analysing the SAXS data by curve-fitting these models has revealed considerable new insight into the morphological response to deformation in these materials and indicated possible links to mechanical and thermal behaviour.

Next up was Mark Farnworth from Pilkington Glass with X-ray reflectivity in the glass industry;

Mark described how the techniques of XRPD, GAXRD, pole figures and X-ray Reflectivity measurements can be used to examine samples from all stages of glass manufacture, from the crystalline raw materials to the amorphous final product.

GAXRD is used to examine thin coatings on the glass surface of hydrophobic coatings, which disperse water.

Refractory materials are examined to determine how much non-crystalline material is present and the amounts of quartz, cristobalite and tridymite.

Also, multi-layer stack coatings are examined E.g. Ti ZrO₂ Ag Si.

Texture maps can be produced which show the degree of texture in the silver layer of the coatings and the thickness, density, top and bottom roughness of each individual layer can be measured.

Finally, Richard Clapperton of Huntsman Surface Sciences Oldbury gave a fascinating insight into the world of detergent research with: SAXS Interpretation of Deflocculated Vesicles - The Route to Superconcentrated Detergents

Richard described how liquid detergents contain concentrated solutions of surfactants and their phase behavior determines the key physical properties of the detergent, such as viscosity and storage stability. Whilst the latter can be measured through techniques such as rheometry, and phase can be identified by optical microscopy, there are few tools available to the formulator to characterize the liquid on a molecular level. Small Angle X-ray Scattering (SAXS) is a fast, versatile technique that enables the finer details of surfactant phases to be determined. This includes confirmation of phase type and measurement of phase dimensions, such as water layer thickness between surfactant bilayers. The effect of additives on phase structure can be monitored by SAXS, thus assisting product development. The challenge of achieving superconcentrated detergents has been greatly simplified by SAXS characterization.

This concluded the SAS sessions and everyone agreed that it had been an enjoyable and successful event.

Richard C.E. Morris
Huntsman Surface Sciences, Oldbury UK.

Instrument Calibration Session “How to be a star”

Photograph of speakers.

Introduction - Dave Taylor and Jim Kaduk

The opening introductory session was shared by Dave Taylor and Jim Kaduk (the new ICDD Chairman). Jim explained the criteria for a star quality pattern in the ICDD powder diffraction file. Dave went on to cover the standards available for instrument testing including non-ambient calibration and gave a reminder of the lists maintained on the IG web pages. The rapid expansion of the PDF is a significant factor in driving us towards better instrument alignment to ensure that phase identification software pulls up the right matches with the push to tighter search windows. The need for testing was demonstrated with examples from the IG Instrument Sensitivity Round Robin and a new spreadsheet will be available soon to automate checks. The basics of instrument alignment were then covered. Dave also announced details of a new low angle Round Robin based on a Ag Behenate film being launched by the IG this summer. Jim rounded off by explaining the procedures for submitting “star” quality patterns to ICDD for all those new compounds currently missing from the PDF database.

Aspects of calibration in SAXS - Manfred Kriechbaum

Manfred covered the difficulties of calibration for SAXS measurements with nothing in the way of absolute standards. Rat-tail (tendon collagen) with a spacing of approximately 67nm is used for checks but it is not very stable especially to moisture. He also gave an overview of the role of SAXS at the Austrian Academy of Sciences.

The European XRPD Standard - Steve Norval

Steve explained the background to this standard. For XRPD, there are different instruments, techniques and applications. It is not the easiest technique to standardize. The motivations for putting together a 'standards' document include good practice, a point of reference for producing acceptable data and demonstrating competence. The title of the document is 'X-ray Diffraction from Polycrystalline and Amorphous Materials'. It has been put together by a working group of a technical committee of the European Commission for Standardisation. 'General Principles' and 'Procedures' documents were released in 2003 under the following codings: BSEN 13925-1 and BSEN 13925-2 respectively. The aim is to release a third document 'Instruments' this year - BSEN 13925-3. Beyond that, documents on 'Reference Materials' and 'Terminology' will be released. Steve gave an overview of the contents of the 'Instruments' document. It covers issues such as types, components, calibration and testing. For the control of a diffractometer there is component selection, component configuration, alignment and testing. Procedures have been established for calibration and instrument alignment/verification.

Lined-Up or Spot-On? The Ups and Downs of Diffractometer Alignment - Martin Vickers

Martin gave a very useful and practical guide to the alignment of the equipment at Birkbeck College which includes both transmission and reflection geometry. Good alignment produces accurate 2-theta positions, maximises intensity and produces nice peak shapes. Useful tricks and a well thought out approach, designed especially to assist Bruker Users in the tricky art of alignment, were well received.

Stress Instruments - Judith Shackleton

Judith gave a good overview of the approach required for residual stress analysis and stressed the importance of accurate results when measurements rely on very small changes in high angle measurements. Additional complications arise with the complex shapes of the components for analysis. Stress is calculated from Hook’s Law [Young's Modulus – Stress/Strain] using the sin²ψ method. In effect, the crystallographic planes act as an atomic scale strain gauge. A stress-free standard is not required and the method is easy to carry out, however, the method is only sensitive to the top few tens of microns of a surface. She explained how an algorithm developed in conjunction with Rolls Royce was being applied to peened samples.

Calibration for Silver Halides - David Beveridge

David explained the problems associated with the photographic industry and the difficulties of resolving phases which requires the very precise measurements of a few lines at moderately high angles. Calibrations are required for peak position, width and peak profile. Peak widths are often variable and depend upon chemical variability, strain and grain size. Often in house standards are required as calibration aids.

The session ended with the chair Jeremy Cockcroft thanking the speakers for their contribution to an interesting session.

Mark Farnworth
Pilkington European Technical Centre

Catalysts in Industry

Photograph of speakers.

X-Ray Diffraction at Johnson Matthey From Cell Parameter to Fuel Cell. Tim Hyde, Johnson Matthey

Johnson Matthey's core products are catalysts, precious metals and specialty chemicals. Tim described the role X-ray diffraction has played over many years in the support of their research and development interests. He described how autocatalysts for either petrol or diesel vehicles are comprised of a ceramic honeycomb support coated with the catalyst. XRD analysis of the coating involves phase ID, Crystallite size and lattice parameter determination of the platinum group catalyst, comprising a platinum group metal catalyst and various promoters on an oxide support. After accelerated aging, XRD has proved a useful tool in determining the efficacy of catalysts towards meeting legislative emission standards.

Highly efficient and clean fuel cell technology is likely to be used in future stationary and mobile power application with catalysts and catalyzed components at their heart. He described the use of platinum alloy catalysts in proton exchange membrane fuel cells (PEMFC) and the relationship between observed enhanced activity, structural features and the x-ray diffraction data.

Catalysts In Situ. Steve Norval. ICI plc.

Heterogeneous catalysts are crucial in making a large proportion of the chemicals we use daily. Steve described how they helped produce the fuel in our cars and clean the exhaust gases. The margarine that many of us eat was oil until it was catalytically solidified. A catalyst is usually defined as a substance that increases the rate of a chemical reaction without itself being changed by it. The reality is not as simple as that and the "science" of catalysts can be more like a black art. Solid catalysts transform chemically and physically as they are activated for use and throughout their life span. Much of the relevant information about the performance is at the level we probe by XRD - phases, crystal structure and microstructure. However, there is always the likelihood that the catalyst in the reactor is not the same as the one put in or the one taken out and that is why the use of in situ measurements are vital to real understanding. Steve used examples of typical catalyst systems to describe of the role of XRD in their characterization.

Powder X-Ray Diffraction and Heterogeneous Catalysis. Justin Hargreaves , University of Glasgow.

Justin gave an academic perspective on the application of powder x-ray diffraction to heterogeneous catalysts. Many published studies have simply concentrated on the identification of catalyst phase composition by standard fingerprint techniques with the consequent loss of the full range of information available. Justin described a number of studies which have concentrated on the deeper understanding of catalytically relevant systems. Particular emphasis was placed on the application of line profile analysis for the determination of microstructural detail with an example from the recent literature on the Cu/ZnO system being cited. The application of Debye Function Analysis to the study of highly dispersed supported metal particles was also reviewed with recent examples of in-situ application being given.
Editor's note: Justin's talk will be featured in a special edition of Crystallography Reviews which will be distributed to all BCA members in 2005.

END OF SPRING MEETING REPORTS Three other 2004 meeting reports follow.

Introduction To Powder Diffraction - One Day Workshop

Manchester Materials Science Centre
10th June 2004

This event was hosted by Judith Shackleton and was aimed at people new to powder diffraction, those with some experience who need a refresher course or those considering the purchase of equipment. Our contingent from Liverpool John Moores University fitted that description perfectly. There were three of us in the party: myself, an academic with some experience of PXRD; a technician who has considerable experience; and a PhD student with none. We have recently purchased a new instrument and were appreciative of the opportunity to receive some training by the expert speakers at this meeting.

The venue was cosy, a seminar room in the Manchester Materials Science Centre. After being welcomed by Judith Shackleton, the first session was an Introduction to Powder Diffraction led by Jeremy Cockcroft. He outlined the differences between single crystal and powder diffraction and gave an overview of the factors that dictate the positions and intensities of peaks on a PXRD pattern.

Judith then discussed instrumentation and sample preparation and gave valuable insights into the operation and maintenance of a powder diffractometer. I had no idea that X-ray tubes lose intensity over time and have to be regularly checked and eventually replaced. She also talked about the importance of good sample preparation and how to overcome the difficulty of small quantities of sample. This was one of the most interesting and useful sessions for me and the smell of the awaiting lunch did not detract from the speaker.

After the buffet lunch, Dave Taylor spoke about the ICDD powder diffraction file and how this came to be the standard way of recording powder diffraction data. He related the history of the system and how it has arrived at its present form and the products currently available.

Jeremy Cockcroft took the floor for a second time to explain how powder diffraction can be used in quantitative analysis. He used a whole range of case studies from minerals to pharmaceuticals to illustrate how the different methods can be applied. For those with some knowledge of structural crystallography, the Reitveld method of refinement of data was discussed.

Judith Shackleton led the final session, which explored the use of other diffraction techniques including neutron and synchrotron techniques and residual stress measurement.

The day included several plenary sessions when the audience could pose questions to the panel of speakers, related either to the material covered or to problems encountered elsewhere. This was one of the most useful aspects of the day with many attendees asking questions and all of the speakers contributing to the answers. These sessions were often extended beyond the allotted time and even sent Judith off to the basement, returning with examples of equipment and sample holders to show the audience.

This workshop was extremely accessible in terms of duration and fee. Long training courses are hard to make time for and finding funds can be difficult. The geography, duration and low cost of this workshop meant that a contingent of three rather than a single representative was able to attend and as a result we were able to consolidate our understanding by discussions after the event. This was a very successful day, which should become a regular entry in the BCA calendar.

Linda Seton
School of Pharmacy and Chemistry
Liverpool John Moores University

Report on BCA Industrial Group - Pharmaceutical SIG Meeting on 5th October 2004.

Photograph of speakers.

This meeting of the Pharmaceutical Special Interest Group was superbly organised by Anne Kavanagh (AstraZeneca) and Roy Copley (GSK), and hosted by AstraZeneca at the company's picturesque Alderley Park site.

After a warm welcome to the meeting by Anne, Rebecca Booth (AstraZeneca) explained the importance of hydrate formation in the development of new drugs and the strategies available for screening compounds for hydrate formation. Whilst vapour sorption studies are very valuable for studying hydration processes that are governed by fast kinetics, they are not so useful for investigation of hydration processes that are under thermodynamic control and for which the kinetics may be slow. Such systems are best studied using a slurry method that relies on the activity of water being directly related to relative humidity. Rebecca illustrated the advantages of the slurry method using two case studies, theophylline and an AZ compound. For both cases, the slurry method proved much faster at assessing the relative stabilities of hydrates and anhydrous forms.

Chris Hunter (University of Sheffield) then explained how 1H NMR methods can be used to study crystal nucleation in solution. The technique was originally developed to obtain structural information from the changes in chemical shift caused by complexation between two components to form a weakly bound complex. Chris explained how the technique can be extended to obtain structural information about molecular aggregates during the initial stages of precipitation. Chemical shifts are calculated ab initio for small molecules and then these are applied to larger molecules. A genetic algorithm approach is used to refine the chemical shifts allowing the structural model to be optimised by comparison of calculated and observed chemical shifts. The technique was illustrated with sulfamerazine, for which the solution-phase aggregate matches very closely the X-ray crystal structure, and carbamazepine for which the solution-phase structure is solvent dependent. In general, the method works well for relatively rigid molecules and for those for which there is an abundance of chemical shift information.

After coffee, Gareth Lewis (AstraZeneca) introduced the importance of salt selection studies in order to optimise the physicochemical properties of a drug. Interestingly even taste can be an important factor, especially for paediatric medicines. Gareth illustrated how remacemide, a potential antagonist for epilepsy, Parkinsonism and Huntingon's disease, was crystallised as a variety of salts that were subsequently investigated by X-ray diffraction. The crystal structures clearly showed hydrophobic and/or hydrophilic regions depending on the nature of the counter-anion. The hydrogen-bond motifs were also analysed. Interestingly, the size and shape of the anions appeared to have very little effect on the types of structure observed.

Ed Collier (formerly UMIST, but now The University of Manchester) continued with the theme of salt selection and described the work performed during his PhD. This involved the preparation of a further 23 salts of the pharmaceutical compound (1R, 2S)-(-)-ephedrine using combinatorial techniques. Ed highlighted that during these crystallisation studies, several of the acids showed variations in their apparent acidity that depended on the solvent. From these salts, 19 crystal structures were obtained and the hydrogen-bonding networks and structure-property relationships were analysed. In addition to hydrogen-bonded motifs it is clear that - stacking interactions play an important role in many of the structures. The work has provided a starting point for a salt screening strategy and has improved understanding of the reasons for success and failure of commonly used anions to provide stable, crystalline salts.

After an excellent lunch and photo opportunity, Chris Gilmore (University of Glasgow) kicked off the afternoon with a presentation about how to identify polymorphs from the results of high-throughput screens that involve computer-controlled crystallisation and data-collection methods. Such data are frequently complicated by the presence of mixed phases, broad diffraction peaks, and preferred orientation. Chris explained how his program PolySNAP can be used to circumvent these problems. The technique relies on point-by-point matching of powder patterns rather than simply by matching peaks. A combination of non-parametric (Spearman) and parametric (Pearson) statistical methods are used to obtain a correlation matrix. This is then used to generate a distance matrix, which acts as a source of classification to generate dendrograms, multidimensional metric scaling, silhouettes, fuzzy clusters and minimum spanning trees. These tools allow the data to be partitioned into clusters of related patterns. The program is very powerful and can readily detect mixtures of phases or components. Chris and his team have extended the technique to include additional data from Raman, infrared, and DSC measurements.

Doug Minick (GSK, North Carolina) then described the chiro-optical technique, of vibrational circular dichroism (VCD) to aid in the assignment of absolute configurations of chiral drug molecules. In VCD, polarised infrared spectra are first recorded for a compound in solution. Because of the time-scale of the infrared technique, contributions from all of the conformers present contribute to the observed spectra. Molecular mechanics calculations are therefore used to identify possible conformers and then ab initio calculations are then used to obtain the relative proportions of conformers present and most importantly the contribution each one makes to the VCD infrared spectra. After correction of gas-phase frequencies to solution-phase frequencies, the experimental and theoretical VCD spectra are compared and conclusions can be drawn about the absolute configuration of the chiral compound. Although the technique has some limitations, Doug currently reported a 96% success rate and he has had 15 assignments subsequently confirmed by X-ray diffraction.

Colin Pulham (University of Edinburgh) finished off the day with a presentation about the use of high pressure as a means of searching for new polymorphs and solvates. Although high pressure is widely recognised in the Physics and Geosciences communities as a powerful means of inducing phase changes, it is not a technique that has been widely explored by the chemical or pharmaceutical communities. Colin illustrated how recrystallisation in diamond anvil cells can be used to prepare and characterise new polymorphs and solvates of phenanthrene, paracetamol, and piracetam. These experiments can be scaled up and in some cases bulk quantities of these polymorphs and solvates can be recovered to ambient pressure. He also demonstrated how the technique can be used to screen for polymorphs by showing that the 3 known forms of piracetam plus a new form can be selectively recrystallised simply by changing the pressure.

Roy Copley concluded the day's proceedings by thanking the speakers and participants, and urged everyone to support the Spring BCA Meeting that will include two sessions on the subject of non-ambient pharmaceutical studies.

Colin Pulham
University of Edinburgh

Autumn Meeting "DIY Crystallography" 4^th Nov 2004

School of Crystallography, Birkbeck College, London.

Photographs of speakers and equipment..

Forty delegates from UK Universities, Commercial and Industrial institutions attended this one-day meeting, organised by the Industrial Group of the British Crystallographic Association (BCA). The meeting was organised into two main sections - Hardware and Software. The speakers addressed the Do-It-Yourself aspects of crystallography which are widespread in the field due to the specialised nature of many activities which are not easily catered for in commercial instruments and software.

Building a High-Resolution Powder Diffractometer (Chiu Tang, DIAMOND)
The synchrotron will have a 'medium' electron beam energy of 3.0GeV. The storage ring has a diameter of 561.6M and it has more than 20 bending magnets. Chiu showed a number of photographs obtained by a colleague flying a model helicopter containing a camera over the site! With 3 diffraction circles its design is highly versatile. The sample chamber is large (40x40x40 cm3) and there is a high precision, heavy-duty, xyz table.

Oscillating a sample for in-situ furnace studies (Olivier Leynaud, Birkbeck College, UCL)
The project is focussed on in-situ experiments using gasses or vacuum at high temperatures. The furnace needs to be able to heat up to 950C and needs to accommodate capillaries with diameters up to 2mm. Different types of oscillating systems were investigated to oscillate, backwards and forwards, capillaries in the furnace: polarity, piston, wheel-like and it was the latter that was selected. Olivier showed some photographs of the completed device. The device oscillates at 68rpm with a 12V battery.

Industrial Polymer Processing Studies using Combined SAXS/WAXS Techniques (Ellen Heeley, Polymer Centre, University of Sheffield).
Ellen began by saying that there is extensive use of polymer films in packaging. Texture is developed during processing but the nucleation in crystallisation is still largely a mystery. Ellen can record Small Angle X-ray Scattering (SAXS) and Wide-Angle X-ray Scattering (WAXS) data at the same time, which can be combined with rheology studies. The main areas for research are quiescent (slow processes) and sheer induced crystallisation / orientation.

Multiple Sample Holders (Mark Farnworth, Pilkington plc).
Mark described two multi-sample holders for the PANalytical Materials Research Diffractometer that he had designed and then had fabricated out of aluminium plate. Use is made of the batch programming software in X'Pert Data Collector. Sample x, y, and z values and the name of the data acquisition program are entered into the 'batch' program. Z values for each sample are determined in the conventional manner, using the dial contact gauge. Mark explained that the plate dimensions had to be carefully calculated to avoid contact with the primary optics and the sample stage.

A Multi-Sample X-ray Diffractometer with Photographic and Counter Recording (Jamie Nelson, Gemmological Instruments).
Jamie described the work that he had carried out on the Debye-Scherrer photographic camera. His passion for tinkering with the camera, attaching items such as proportional counters, eventually led to him to receive Fellowship of the Institute of Physics. Jamie described several aspects of diffractometry hardware and used, for a relatively younger audience, unfamiliar terms such as Hole, Slot and Plane mounting or the 'Kelvin Mount'.

MATLAB: A Software Tool for Quick Data Analysis (Christopher Hall, University of Edinburgh).
Christopher described his use of MATLAB 7. He finds several features particularly useful. These include good data input/output, built in utilities and functions, scripting (the stitching together of MATLAB commands into small programs) and a good graphic environment for reports and producing a common 'house' style. Christopher has built up a collection of scripts and utilities for handling synchrotron diffraction data - called XMAT.

Sharing Software Toolkits (By Ron Ghosh, ILL).
Ron explained that over the last thirty to forty years there have been numerous computer languages from 'Plot 10' in the 1960's to modern day 'Windows'. Many of the packages have individual scripting languages and so this, and other complications, often deter the 'novice' from getting involved. He gave a simple demonstration of the use of Fortran for data display, plotting and filtering routines. Individual peaks can be selected for analysis e.g. line broadening. Ron finished the presentation by giving a number of useful internet links (see web version of report).

DIY Single Crystal Structure Analysis (Richard Cooper, University of Oxford)
Richard described the use of the 'Crystals' package for the analysis of single and twinned X-ray/Neutron Diffraction data. There are three main areas, Guidance, Validation Criteria and Tools. The Guidance step covers data collection (initial hkl analyses), early refinement, getting a complete model, later refinement, weightings and publication. The script language can access any crystal data or results. The Cambridge Structural Database (CSD) can be used to validate chemical geometry.

CCP14 Developments (Richard Stephenson, UCL, Birkbeck College).
The CCP14 website at www.ccp14.ac.uk contains freely available software, including state of the art algorithms and utilities. There is a concentration on crystallography. User feedback optimises the direction of the project. CCP14 contains multiple single crystal suites and multiple powder indexing programs and suites. It has 60GB of software and help files and has 35,000 monthly hits. It has a 'wiki' component (!) by which users can add comments that can be edited by any other user. Thus, the quality of the data is continually refined and improved.

Making do without the JCPDS (David Beveridge, Ilford).
David gave a series of steps that could be used to identify a diffraction pattern without the use of the JCPDS database. A good prior understanding of the sample would be ideal since this could drastically reduce the number of options for identification. A local library of patterns from reference materials can then be used for the search. A good understanding of the crystalline components in common materials would also be helpful. For example, paints contain rutile and anatase titania, kettle fur, soil and building dust contain calcium carbonate (calcite) whereas plaster contains hydrated calcium sulphate (gypsum).

CRYSFIRE Update (Robin Shirley, University of Surrey)
Indexing a powder pattern may only be a 6-parameter problem, but can still be a challenge. While methods of treating data have improved greatly, there is till great reliance on high data quality. Robin described the new CRYSFIRE now includes ten indexing programs with different approaches, nd gives figures of merit for 10 or more indexing patterns. The newest version works with Windows XP.

Mark Farnworth
Pilkington European Technical Centre

Last updated 03-February-2005

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